Buggy code:
@ SuppressWarnings ( "deprecation" ) public class Util { static PlotAPI plotAPI = null ; public static PlotAPI getPlotAPI ( ) { } public static Essentials ess ; public static void LoadEssentials ( ) { } public static void CreatePlotSkull ( Plot plot , String owner , Location l1 , Location l2 , Location l3 , Location l4 ) { } public static void RegisterPlotCommands ( ) { } public static void line ( org . bukkit . Location l1 , org . bukkit . Location l2 , Material material ) { } public static String parseColors ( String message ) { } public static boolean contains ( char [ ] array , Character character ) { } public static String getItemName ( ItemStack is ) { } public static Permission getPermissions ( ) { } public static boolean isIn ( org . bukkit . Location loc1 , org . bukkit . Location loc2 , org . bukkit . Location loc3 ) { } public static ItemStack newItemMeta ( Material material , String name , String lore , int amount ) { } public static ItemStack newItemMeta ( Material material , String name , String lore , int amount , short durability ) { } public static void initScoreboard ( ) { } public static ChatColor getGroupColor ( String group ) { } public static Main getMain ( ) { } public static Server getServer ( ) { } public static FileConfiguration getConfig ( ) { } public static String [ ] playerInventoryToBase64 ( PlayerInventory playerInventory ) throws IllegalStateException { } public static String itemStackArrayToBase64 ( ItemStack [ ] items ) throws IllegalStateException { } public static ItemStack [ ] itemStackArrayFromBase64 ( String data ) throws IOException { } public static void setGlobalKit ( Player player , String name ) { } public static void removeGlobalKit ( String name ) { } public static boolean hasJoined ( Player player ) { } public static boolean containsIgnoreCase ( String message , String regex ) { } public static boolean startsWithIgnoreCase ( String message , String regex ) { } public static org . bukkit . Location getLocation ( Location location ) { } public static void suspend ( Player player ) { } public static void removeSuspend ( Player player ) { } public static void setAllOnlineTimes ( ) { } public static void loadOnlineTime ( Player player ) { } public static void loadAllOnlineTimes ( ) { } public static void updatePlayerList ( ) { } public static void sendAdminMessage ( String message , Player sender ) { } public static FileConfiguration getOfflinePlayerFile ( String name ) { } public static String buildString ( Collection < String > args , String seperator , int startingArg , int maxLength ) { List < String > retList = new ArrayList < String > ( ) ; String ret = "" ; for ( int i = startingArg ; i < ( args . size ( ) ) ; i ++ ) { String s = ( ( String ) ( args . toArray ( ) [ i ] ) ) ; ret += s + seperator ; if ( ( ret . length ( ) ) > maxLength ) { retList . add ( ret ) ; ret = "" ; } } retList . add ( ret ) ; ret = "" ; for ( String s : retList ) { ret += s + "\n" ; } <START_BUG> if ( ( ret . length ( ) ) > 0 ) { <END_BUG> ret = ret . substring ( 0 , ( ( ( ( ret . length ( ) ) - 2 ) - ( seperator . length ( ) ) ) + 1 ) ) ; } return ret ; } public static boolean isVerified ( String key ) { } public static void addKey ( String key ) { } public static void removeKey ( String key ) { } public static String addRandomKey ( ) { } public static boolean isURL ( String s ) { } public static boolean isPlayerName ( String s ) { } }

Fix:
if ( ( ret . length ( ) ) > 2 ) {